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No No Go Wide ratio w 3.08
BUT what about the engine torque curve?
The Rev.
BUT what about the engine torque curve?
The Rev.
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WHO CARES ?
Low......High............Who Cares?
The Rev.Comment
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Re: No I want to know How low
I am talking numerical value. That is the number I have to use when I order a gear. . Has any body tried a add-on a overdrive. I bet we are talking a lot of money here, and a lot of work.Comment
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Re: How low can You go?
Andy, you want to use a higher gear ratio (ie lower numerical) with a wider ratio gearbox, so you get better acceleration in first gear. The other gears are all the same between CR and WR tranny's. So, the overall gas mileage and cruising RPMs will be the same in 4th gear, as both (CR and WR)have a 1:1 ratio in 4th. You probably want to stick with a 3.36 pumpkin, as if you go any higher (numerically lower ie 3.08) you wont have a lot of torque to the wheels off the line. If you had a higher horsepower engine, then you could get away with a higher ratio (lower number) in the back.
Hope this helps.
BrandonComment
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Re: How low can You go?
Mornin' Andy,
Lot's of good information here, but you might want to borrow (if possible) a friends stright axle Corvette that has the combination you are interested in installing in yours. If your friends car provides acceptable performance, go for it.
If your only priority is milage and hiway crusing and you almost never drive in town, your planned change to a 3.08 or higher is OK. Just be aware that your 270 HP, 283 incher is going to produce so little torque at the RPM you will be operating in that the car will be VERY sluggish at any RPM less than 3000. Also, starting from a stop with a CR tranny and a 3.08 or higher is going to "kill" your clutch if you do any town driving. I'll go out on a limb here and make a bet that Dave,s car (with 3.08's and CR trans) has a big block in it. Torque makes all things possible, I question whether you have the torque required to make this a "happy" combination. Let us know what you do. BillComment
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Re: How low can You go?
Is there any way, with out breaking down the tran. to tell is you have a 2.20:1 or a 2.54:1 first gear?Comment
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See? There is someone who cares....
so there!Comment
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Re: How low can You go?
If you had a higher horsepower motor, with resultant poorer low end torque, you would be REQUIRED to have a higher numerical ratio (like a 4:11) in order to start the car rolling without stalling or bucking the motor.
The Rev.Comment
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Re: How low can You go?
Andy:
Just install a 3.70 or 3.55 rear end and forget it. That'll get ya a ballsy street machine with your engine and you should have reasonable fuel economy. If I were you I'd opt for a 3.70.
The Rev.Comment
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Re: It's The Peter Principle- Promoted To Incompet
Chuck -- «What else can they do with old, seasoned (hard-headed) veterans except shove them up the ladder or lay them off. »
Well, in my case, I got laid off. In '88. Went from upper-middle management to engineer. But I then got mail addressed to "Resident Genius". Since I have retired, my new title is "Genius Emeritus." So there. Too.
GeezerComment
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Re: How low can You go?
A 270 with a 4.11 should have a CR as OEM. To check shift from third to fourth at 3000 RPM. With a CR the revs will drop to about 2100. With a CR they will drop to about 2300. Early CR ratios are 2.20, 1.64, 1.31, 1.00. WRs varied slightly over the years but the early one's are about 2.54,1.89.1.48,1.00. The difference between the CR and WR was basically the gap between third and fourth.
DukeComment
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Re: How low can You go?
Who says you have to have poor low end torque with a higher horsepower motor?
BKComment
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Free At Last, Free At Last
Hey Geez,
Me too! I did both. But, I could never get that ladder-climbing technique down pat; kept missin' the rung and bustin' my nose. Ulitmately, I decided I had enough, having scrimped and saved, not to mention marrying well.
Since the labor market has gotten so tight, they've taken to resuscitation of dead bodies in the cemetary; I get calls wanting to know if I want to work again. Heck, I say, I'm having fun; Why should I come back and have to deal with you butt-heads every day. Whoo-Hoo!
Chuck SangerhausenComment
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Re: How low can You go?
God! Basic physics. Don't be misled by semantics. What is Low? What is adequate?
The Rev.Comment
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DUKE IS RIGHT
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